Thermoplastic adhesives

ABSTRACT

A thermoplastic adhesive comprising an intimate mixture of 100 parts of a thermoplastic polymer and 0.01-10 parts of a chelate of an aminoacetic acid or an aminopropionic acid and a polyvalent metallic ion, the chelate being free of acid hydrogen ions.

United States Patent 1191 Mar-ans Jan. 21, 1975 THERMOPLASTIC ADHESIVES [56] References Cited I [75] Inventor: Nelson S. Marans, Silver Spring, UNITED STATES PATENTS Md. 3,135,722 6/1964 Logemann 260/855 M 3,141,869 71964 D tdt [73] Asslgnee: x & New Ymk, 3.515,?09 6/1970 012112 1111111 260/8911 [22] Filed: Dec. 12, 1973 Primary ExaniinerHarry Wong, Jr. pp O 424,238 gfitggrezey, Agent, or Firm-E1t0n Fisher; Kenneth E.

[52] US. Cl 260/93.7, 117/161, 161/182, [57] ABSTRACT 161/203 161/216 161/247 161/250 A thermoplastic adhesive comprising an intimate mix- 161/252 250/873 260/8911 260/9218 ture of 100 parts of a thermoplastic polymer and 260/949 GA, 260/94 GB ().()1-l0 parts of a chelatc of an aminoacetic acid or 51 11 1. (:1. C081 29/02, C08f 45/72 an aminopmpionic acid and a polyvalcm metallic ion [58] F'eld Search "260/928 the chelate being free of acid hydrogen ions.

94,9 GB,260/89.l, 93.7

10 Claims, No Drawings THERMOPLASTIC ADHESIVES BACKGROUND OF THE INVENTION This invention is in the field of ahesives. More particularly, it is in the field of thermoplastic adhesives. Still more particularly said invention is an improved thermoplastic adhesive useful as a hot melt adhesive.

SUMMARY OF THE INVENTION In summary this invention is directed to a composition comprising an intimate mixture of 100 parts of a thermoplastic polymer and 0.0l-l parts of a chelate of;

a. an amino acid selected from a first group consisting of o noi'zmn g o R N CH con [N l I socma g ca y con o 0 aoctca I /(CH2 con -CH2-C-CH2N noemn g, 3 (cra y con H H H H I I I I R I-NCH CH -N-C 1-R COH COH II II 0 0 in which;

i. R ia an alkylene group having 2-10 carbon atoms;

(ii) R2 OH, HOC@OH, HO 0 ,-oH, or CH 0 OH;

However, we have found that excellent results can be obtained where the methyl group of CH -@-OH is replaced with a lower alkyl group or with an alkyl group having up to 8-10 carbon atoms. Such alkyl groups are equivalents of said methyl group.

DESCRIPTION OF PREFERRED EMBODIMENTS In preferred embodiments of the invention recited in the above Summary:

1. The thermoplastic polymer is high density polyethylene, polypropylene, polyvinyl acetate, or polyvinyl chloride.

2. There is 0.l2 parts of the chelate per parts of thermoplastic polymer.

3. The first group member is /N Rl-If (CH2; CQH rioctcn g, (c11 con wherein x is 0 and y is l and the second group member is tin, cadmium, lead, titanium, iron, or barium.

4. The first group member is a warm, 0

/N R -If (CH2? 80H acctca g, (CH8, con

wherein (a) x is 1; (b) y is 1; and (c) R is CI-I CH and the second group member is tin, cadmium, lead,

titanium, iron, or barium.

5. The first group member is sauca I (cH con CH2C-CH2N anzztcn g g (ca i, on

wherein y is l and the second group member is tin, cadmium, lead, titanium, iron, or barium.

6. The first group member is wherein or noc- 0 -on;

and the second group member is tin, cadmium, lead, titanium, iron, or barium.

DETAILED DESCRIPTION OF THE INVENTION It is an object of this invention to provide an improved or superior thermoplastic adhesive composition.

It is another object of this invention to provide such superior adhesive by admixing a thermoplastic polymer and a chelate of an aminoacetic or aminopropionic acid of the type recited in the above Summary and/or the above Preferred Embodiments.

The improved thermoplastic adhesive of this inven tion is especially useful for laminating meta] foils to plastic films (to prepare laminates useful for packaging foods and other items), for sealing side seams of metallic cans, for sealing packages, and the like.

Metallic chelates (chelates of chelating aminoacids and polyvalent (including divalent) metallic ions are well known to those skilled in the art. Such chelates can be prepared by a number of well known methods including:

l. Reacting, in an aqueous system, an oxide ofa polyvalent (including a divalent) metal with the free amino acid. By using substantially stoichiochmetric amounts of amino acid and oxide the resulting chelate is free of acid hydrogen ions and unreacted metallic oxide. If the chelate is insoluble in water, it can be recovered by filtration, decantation, or centrifugation and dried. If the chelate is soluble, the water can be evaporated from the aqueous reaction product to leave the chelate behind.

2. Reacting a salt of a polyvalent (including a divalent) metal with a chelating amino acid in an aqueous system, adjusting the pH with base to give maximum stability to the metal chelate, and recovering the resulting chelate. This method is especially useful to form chelates of polyvalent metallic ions (such as iron (lII)) whose oxide is insoluble.

Various other methods for preparing the chelates used in this invention will be readily apparent to those skilled in the art.

I prefer to form the composition of this invention by admixing the metallic chelate and the thermoplastic polymer .in a Brabender mixing apparatus for a' period of about 5 minutes. I have found that a mixing temperature of 200C is preferred for polypropylene, high density polyethylene, and polyvinyl chloride. I have also found that a temperature of about 150C is sufficient for low density polyethylene and for ethylene-vinyl acetate copolymers. One of ordinary skill in the art can readily determine the preferred mixing temperature for any thermoplastic polymer. Such temperature is below the decomposition temperature of the polymer and above its melting point.

In no instance did the addition of a chelate to any of the thermoplastic polymers tested give polymer decomposition or crosslinking. On the contrary, the torque, while operating the Brabender apparatus at a constant speed remained constant, thereby indicating an absence of decomposition or crosslinking which would have changed the torque. Where mixing polyvinyl chloride about 3 percent, based on the weight of the polyvinyl chloride, of a commercially available polyvinyl chloride stabilizer (Advastab T-l7M obtained from Cincinnati Milacron Chemicals, Inc.) was included in the mix because decomposition occurred in a trial run, using polyvinyl chloride without chelate and without stabilizer.

The composition of this invention can be used as a hot melt adhesive. It can be used to bond wood to wood, wood to metal, wood to concrete, wood to plastic, metal to metal, metal to plastic, plastic to concrete, ceramic material to ceramic material, wood to ceramic material, wood to glass, glass to ceramic material, plastie to glass, plastic to papenand the like.

The instant invention will be better understood by referring to the following specific but nonlimiting examples. It is understood that said invention is not limited by said examples which are offered merely as illustrations; it is also understood that modifications can be made without departing from the spirit and scope of the invention.

EXAMPLE l part of high density polyethylene and 1 part of an ethylenediaminetetraacetic acid chelate of titanium having the formula (EDTA)Ti, in which EDTA is was blended in a Brabender mixing apparatus for 5 minutes at 200C, a temperature above the polymers melting point, to form an improved thermoplastic adhesive of this invention. Said improved thermoplastic adhesive was removed from the mixing apparatus, recovered and designated Adhesive 1.

A 1.08 g portion of said Adhesive l was pressed using a Carver press at 200C, a temperature above the polymers melting point, into a sheet having an area of 36 square inches. Said sheet was cooled below its melting point and a portion of it was used to heat seal two overlapping tin-free ether-washed steel coupons to each other. Each coupon was 13 mils thick and the lapped (sealed) area was 1 square inch.

The lap shear (a measure of bonding strength) of the sealed steel coupons was measured on an Instron testing apparatus and found to be 722 psi. This contrasts with a value of 91 psi obtained with high density polyethylene from the same lot but without the chelating agent.

EXAMPLE 2 A number of runs was made using the general procedure of Example I. Said procedure was modified as indicated in the following table which reports the results of said runs. Among such modifications are:

1. Using for each run the chelate and polymer listed for such run. (Control runs were made as indicated in said table without the addition of a chelate and some runs were made using the chelate or polymer of Example 1.)

2. Using in some runs (as indicated in said table) ether-washed aluminum coupons rather than tin-free ether-washed steel coupons.

3. Using a mixing (blending) temperature and a pressing temperature of l50F where blending or pressing low density polyethylene.

Run

- EDTANa Chelate None EDTANa Cu (2) NTANaCa (l) NTA(NH Zn (1) NTANaMn (l) NTANaPb (l) EDTAPb (2) EDTANaFe (2) EDTPTi (4) EDTPBEI (4) N'IPFe (5) (NTP) C0 (5) an nn' None EDTASn (2) NTANaPb (l) IMPROVED ADHESIVES co Ba Polymer High Density Tin-Free Steal Polyethylene Polyvinyl Chloride Polyvinyl Chloride High Density Tin-Free Steel Polyethylene Low Density- Polyethylene Composition of Coupon Lap Shear, Psi

(continuation) IMPROVED ADHESIVES Run No. Chelate Pol mer Composition of Coupon Lap Shear, Psi 1 31 None Polyvinyl Tin Free Steel 263' Acetate 32 EDTASn (2) 326 33 EDTANaFe (2) I Y 345 34 EDTACd (2) 402 35 (3) None Polyvinyl Aluminum 102 Chloride 3e (3) EDTAHFe (2,10) I I V 0 37 (3) EDTANa Cd (2) 38 (3) ED'IAH Cd (2,10) 1 39 (3), I NTAHBa 1, 10) Polyvinyl Aluminum 5 i Chloride 4o (3) N'I'ANaBa (1) I 1 v I I 460 41 (3) NTANaCa (1) I 281 42 7 None Polyvinyl 9 1 175 Acetate 43 EDTASn (2 284 44 EDTATi- (2) I n n 298 45 EDTPBa 4 v 275 46 EDTPC02 (4) v v 47 nn'rpn co (4,10 7

4a ED'I'PNa Co (4) 1 304 49 (9) None Low Density 675 Polyethylene so (9) NTANaPb (1) I u 722 '51 (9) 0; Density Aluminum 95o Polyethylene z'e' z z' 'fi z af'e CO CD I I 9 a (8) I I I I Zfi' 2 2' 2 HFe 0 CO CO I I 0 o (8, 1(1) 53 (9)/ 11-5.. 2 a g y l I 4; I3 I 'CBZCHZ N 9 2 Ba 1,108

CO co i n 0 0 (11).

I I 'v I -c-u-ca a2 ZCHZ N 9 2 Ba 1 1,140

CO co I I (continuation) IMPROVED ADHESIVE-S ans: 1 A e Footnotes to tables Polymer High Density Tin-Free Steel Composition of Coupon Lap Shear, Psi

Polyethylene l. NTA means the nitriotriacetate anion, N-(CH COO) 2. EDTA means the ethylenediaminetetraacetate anion,

3. 3% of a stabilizer (Advastab T-l7M obtained from Cincinnati Milacron Chemicals Inc.) based on the weight of the polyvinyl chloride was included in the mix.

4. EUIP means the ethylenediaminetetrapropionate anion,

(0OCCH CH (-NCH CH N)(CH CH COO) 2 I 5. NT? means the nitrilotripropionate anion, N-(CH CH COOl 6. R is 0 iron.

9 Mixing (blending) temperature and pressing temperature were 150C.

10. This run shows the adverse effect of free hydrogen ions. 11. R is GEE-@014.

12. R is n-C H 13... y is l. M

14. y is 2.

As used herein the term g means gram or grams.

As used herein the term psi means pounds per square inch.

As used herein the term mole has its generally accepted meaninga mole of a substance being that quantity of the substance which contains the same number of molecules of the substance as there are carbon atoms in 12 g of pure C.

As used herein EDTP means the ethylenediaminetetrapropionate anion, (OOCCH -NCH CH CH- N--(CH CH COO) As used herein NTA means the nitrilotriacetate anion, N-(CH COO) As used herein NTP means the nitrilotripropionate anin,

1 claim:

1. A hot melt adhesive composition consisting essentially of an intimate mixture of 100 parts of a thermoplastic polymer selected from the group consisting of high density polyethylene, low density polyethylene, and polypropylene and 0.01- parts of a chelate of:

a. an amino acid selected from a first group consisting of no mn ki: 1 0

i. R, is an alkylene group having 2-10 carbon atoms;

0 II (ii) is @wu, Hoc-@-on, Hso @-ot1 or ca ?-oa;

iii. x is O or an integer from 1 to 4; and iv. y is l or 2; and b. a metallic ion selected from a second group consisting of titanium, barium, cadmium, iron, manganese, lead, tin, copper, cobalt, zinc, or calcium the chelate being free of acid hydrogen ions.

2. The composition of claim 1 in which there is 0.1-2.0 parts of the chelate per 100 parts of thermoplastic polymer.

3. The composition of claim 1 in which the first group member is e soctca g 2 Emma l N{R l;l (cn g COH g, tcu g con 0 II 0 x wherein x is 0 and y is l.

4. The composition of claim 3 in which the second group member is tin, cadmium, lead, titanium, iron, or

barium.

5. The composition of claim 1 in which the first group member is k R e -11 (CH8 con D K0E(CH g (30H wherein (a) x is l; (b) y is l;and (C) R is CH CH 6. The composition of claim 5 in which the second group member is tin, cadmium, lead, titanium, iron, or barium.

7. The composition of claim 1 in which the first group member is a a a a I l I I R -c-N-cr1 cH N-c-R con cos I v I o o wherein y is l.

8. The composition of claim 7 in which the second group member is tin, cadmium, lead, titanium, iron, or barium.

9. The composition of claim 1 in which the first group member is or nocQ-on.

10. The composition of claim 9 in which the second group member is tin, cadmium, lead, titanium, iron, or

Page 1 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION DATED January 21, 1975 l on 8. MaranS It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 7 (Column 14) delete H H H H i l I I r u a It R 9 N CH CH N e R COH COH II II and replace the deleted material with O 0 II II HOC (CH2) H (CH g COH omitting the word ["or"] as printed in Claim 9.

Page 2 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 5,862,099 Dated January 21 1975 l e t Nelson S. Marans It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 9 (Column 14) delete HOC (CH2 H (ca g COR 0 N-CH2- o CH2-N n HOS (CH 3 (CH fox-1 O O ,or

and replace the deleted material with H H H H I I I I R :-N-cH cH -N-e-R COH COH II II Signed and sealed this 15th day of July 1975.

(SEAL) Attest:

C, MARSHALL DANN RUTH G. MASON Commissioner of Patents Attesting Officer and Trademarks FORM P0-1050 (10-69) USCOMM-DC 60376-P59 US. GOVERNMENT PRINHNG OFFICE: 869- 930 

2. The composition of claim 1 in which there is 0.1-2.0 parts of the chelate per 100 parts of thermoplastic polymer.
 3. The composition of claim 1 in which the first group member is
 4. The composition of claim 3 in which the second group member is tin, cadmium, lead, titanium, iron, or bariUm.
 5. The composition of claim 1 in which the first group member is
 6. The composition of claim 5 in which the second group member is tin, cadmium, lead, titanium, iron, or barium.
 7. The composition of claim 1 in which the first group member is
 8. The composition of claim 7 in which the second group member is tin, cadmium, lead, titanium, iron, or barium.
 9. The composition of claim 1 in which the first group member is
 10. The composition of claim 9 in which the second group member is tin, cadmium, lead, titanium, iron, or barium. 